Research On Tandem Matching And Explosion Interrupter Mechanism Of Full-caliber Shaped Charge

Aiming at enhancing the damage effect, this thesis took the full-caliber tandem shaped charges warhead as the research subject to carry out a study on the design method of tandem matching, the optimization of front and rear penetrators, the explosion interrupter mechanism of front and rear charge, and the damage effect of tandem shaped charges penetrating armored targets, through which provided theoretical and technical foundations for establishing the systemic design method of tandem shaped charges warhead.This study contains the following main contents and results:(1) The front and rear shaped charge matching conditions was proposed through the study on the tandem matching relation of full-caliber shaped charge which mainly contained the matching relation between delay initiation time and system parameters, and the penetration power matching of two jets. The results showed that rear jet tip velocity and the velocity consumption after rear jet tip penetrating into explosion interrupter device have slight effects on the delay initiation time. The selection ranges of the other parameters that can satisfy their matching conditions were acquired:the tail velocity of front jet is 1500m/s-2000m/s; the charge interval is between 2Dk and 3Dk (Dk stands for the charge diameter); the distance between the rear charge and explosion interrupter device is no less than the charge diameter; the stand-off distance of front charge is between 1.5Dk and 2Dk.The calculation result of the power matching manifested that the front charge should meet the requirement of large hole diameter and deep penetration under the condition of small stand-off distance, and the rear charge requires large stand-off distance to realize its penetration ability. The formation and penetration process were simulated and studied with the help of these data which improved the feasibility of the overall scheme of the study.(2) The formation and penetration properties of the tandem shaped charges warhead front rod type jet was researched. With the detonation wave collision theory introduced into the improved PER theory, the parameters variations such as the collision pressure of different parts of liner configuration, collapsing velocity, jet velocity and mass were studied by theoretical analysis and numerical simulation. The eccentric semispherical liner shaped charge structure with a foam was designed by using orthogonal method, and the tapered liner which was thick in the top and bottom, thin in the middle section can meet the requirement of large hole diameter and deep penetration. The mass of rod type jet that were formed from structure with the above elements was increased by 29.5%, and the tip velocity was increased by 21.3%. At the same time, there existed a certain increase at the tail velocity. Small stand-off distance penetration experiment was carried out to realize the optimization of structure, and significant improvement existed in the penetration property.(3) The charge structure of rear biconical liner was optimized. The effect rule that the top cone angle, wall thickness, liner height of the biconical liner, and height ratio of top cone influenced the tip velocity of the jet, inflection velocity, positions of tip and inflection were studied based on the gray relation theory. At the same time, the selection range of all the optimized parameters was obtained. The accuracy of theoretical and simulation results were proved via X-ray imaging experiment. A penetration depth theoretical model considering the factors of shock wave, jet velocity distribution and jet state was established and the accuracy of forecasting the penetration depth was verified. The influences of demarcation points on penetration depth were compared and the rules of stand-off distance and biconical liner structural parameters influencing the penetration depth are obtained. The penetration rule of biconical liner shaped charge was studied under the condition of large stand-off distance, moreover, the penetration depth empirical model which matched the top and bottom cone angle, and the stand-off distance were established.(4) The attenuation property of the shock wave generated from the front charge in the explosion interrupter structure was studied. By adopting one-dimensional shock wave theory, the initial shock wave parameters and attenuation in the explosion interrupter structure were computed, and the coefficient of attenuation increased with the increase of impedance of the explosion interrupter material. Multilayered media explosion interrupter structures which were composed of sequential impedance, reverse impedance and hard-soft-hard were designed by adopting 45# Steel, Ly-12 Aluminum and PMMA. The shock wave Hugoniot equation and isoentropic flow Murnaghan equation were used to calculate the reflection and transmission process of shock wave, and the shock wave pressure histories on different interfaces were measured by manganin pressure-resistance sensor. The results showed that the output shock wave pressure which was caused by reverse impedance is the minimum, and the explosion interrupter structure with the convex feature can weaken the energy.(5) The explosion interrupter mechanism of tandem shaped charges warhead was studied. The assessment method of multilayered media explosion interruption effect was established based on heterogeneous explosive shock initiation criteria, and the rules of explosion interruption material, charge diameter and explosive material behavior influencing the explosion interruption effect were obtained. The response of rear charge influenced by shock load was researched via numerical simulation. The energy transmission and distribution in multilayered media were analyzed. The explosion interrupter effects influenced by the sequencing, thickness distribution, and total thickness of multilayered media were studied, and the results indicated that the materials with better energy absorption property is more suitable to be the first layer of explosion interrupter structure and it is more beneficial for explosive stability to choose the materials with better energy resistance property to be the second layer. Besides, the materials with better energy absorption property should occupy larger percentage, and the multilayered media with increasing impedance conveys the optimal effect. The explosion interrupter and tandem penetration experiments of tandem shaped charges warhead were carried out.